factor out getTrieNodesForCall

scripts/lib.js

 const fs = require("fs")
+const { hasUncaughtExceptionCaptureCallback } = require("process")
 
 async function deploy() {
   const MIPS = await ethers.getContractFactory("MIPS")
@@ -15,4 +16,37 @@ async function deploy() {
   return [c,m,mm]
 }
 
-module.exports = { deploy }
+async function getTrieNodesForCall(c, cdat, preimages) {
+  let nodes = []
+  while (1) {
+    try {
+      // TODO: make this eth call?
+      // needs something like InitiateChallengeWithTrieNodesj
+      let calldata = c.interface.encodeFunctionData("CallWithTrieNodes", [cdat, nodes])
+      ret = await ethers.provider.call({
+        to:c.address,
+        data:calldata
+      });
+      console.log(ret)
+      break
+    } catch(e) {
+      const missing = e.toString().split("'")[1]
+      if (missing.length == 64) {
+        console.log("requested node", missing)
+        let node = preimages["0x"+missing]
+        if (node === undefined) {
+          throw("node not found")
+        }
+        const bin = Uint8Array.from(Buffer.from(node, 'base64').toString('binary'), c => c.charCodeAt(0))
+        nodes.push(bin)
+        continue
+      } else {
+        console.log(e)
+        break
+      }
+    }
+  }
+  return nodes
+}
+
+module.exports = { deploy, getTrieNodesForCall }

test/challenge_test.js

 const { expect } = require("chai")
 const fs = require("fs")
-const { deploy } = require("../scripts/lib")
+const { deploy, getTrieNodesForCall } = require("../scripts/lib")
 
 describe("Challenge contract", function () {
   if (!fs.existsSync("/tmp/cannon/golden.json")) {
@@ -20,7 +20,7 @@ describe("Challenge contract", function () {
     const blockchain = hardhat._node._blockchain
 
     // get data
-    const blockNumberN = (await ethers.provider.getBlockNumber())-1;
+    const blockNumberN = (await ethers.provider.getBlockNumber())-2;
     const blockNp1 = blockchain._data._blocksByNumber.get(blockNumberN+1)
     const blockNp1Rlp = blockNp1.header.serialize()
 
@@ -30,31 +30,14 @@ describe("Challenge contract", function () {
     let preimages = Object.assign({}, startTrie['preimages'], finalTrie['preimages']);
     const finalSystemState = finalTrie['root']
 
-    let cdat = c.interface.encodeFunctionData("InitiateChallenge", [blockNumberN, blockNp1Rlp, assertionRoot, finalSystemState, 1])
+    let args = [blockNumberN, blockNp1Rlp, assertionRoot, finalSystemState, 1]
+    let cdat = c.interface.encodeFunctionData("InitiateChallenge", args)
+    let nodes = await getTrieNodesForCall(c, cdat, preimages)
 
-    while (1) {
-      try {
-        // TODO: make this eth call?
-        // needs something like InitiateChallengeWithTrieNodesj
-        await c.CallWithTrieNodes(cdat, [])
-        break
-      } catch(e) {
-        const missing = e.toString().split("'")[1]
-        if (missing.length == 64) {
-          console.log("requested node", missing)
-          let node = preimages["0x"+missing]
-          expect(node).to.not.be.an('undefined')
-          const bin = Uint8Array.from(Buffer.from(node, 'base64').toString('binary'), c => c.charCodeAt(0))
-          await mm.AddTrieNode(bin)
-          continue
-        } else {
-          console.log(e)
-          break
-        }
-      }
+    // run "on chain"
+    for (n of nodes) {
+      await mm.AddTrieNode(n)
     }
-
-    //const blockHeaderNp1 = getBlockRlp(await ethers.provider.getBlock(blockNumberN+1));
-    //console.log(blockNumberN, blockHeaderNp1);
+    await c.InitiateChallenge(...args)
   })
 })
\ No newline at end of file